CD_MODEM_SIG_REQ

Section: Communications Device Interface (CDI) (7)
Updated: 2008-10-31
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NAME

CD_MODEM_SIG_REQ - assert modem signals

SYNOPSIS

This primitive consists of one M_PROTO(9) message block structured as follows:

typedef struct {
    cd_ulong cd_primitive;
    cd_ulong cd_sigs;
} cd_modem_sig_req_t;

DESCRIPTION

This user originated primitive requests that the CD provider assert or deassert the specified modem leads and signals.

Parameters

This primitive contains the following parameters:

cd_primitive

Specifies the primitives type.

cd_sigs

Specifies the signals to assert or deassert, and is a bitwise OR of the following flags.

CD_DTR: Data terminal ready.
CD_RTS: Request to send.
CD_DSR: Data set ready.
CD_DCD: Data carrier detect.
CD_CTS: Clear to send.
CD_RI: Ring indicator.

If the flag is set in cd_sigs, the corresponding lead will be asserted. If the flag is clear, the corresponding lead will be deasserted. Flags that are not output leads and are input leads only (such as CD_DCD) are ignored.

State

This primitive is valid in any state other than CD_UNATTACHED or CD_UNUSABLED, and where a local acknowledgment is not pending. The state remains unchanged.

RESPONSE

This primitive requires the CD provider to acknowledge receipt of the primitive as follows:

Successful: Upon success, the CD provider acknowledges receipt of the primitive with a CD_OK_ACK(7) primitives. The state remains unchanged.

Unsuccessful (non-fatal errors): Upon failure, the CD provider acknowledges receipt of the primitive with a CD_ERROR_ACK(7) indicating the reason for failure in the error number. The state remains unchanged.

ERRORS

Non-Fatal Errors: applicable non-fatal errors are as follows:

[CD_BADPRIM]: Unrecognized primitive.
[CD_EVENT]: Protocol-specific event occurred.
[CD_FATALERR]: Device has become unusable.
[CD_NOTSUPP]: Primitive not supported by this device.
[CD_OUTSTATE]: Primitive was issued from an invalid state.
[CD_PROTOSHORT]: M_PROTO block too short.
[CD_SYSERR]: UNIX system error.

FILES

HISTORY

The Communications Device Interface first appeared in SVR 4[1].

CONFORMANCE

This interface conforms to CDI with Gcom extensions.

REFERENCES

[1]: SVR 4, UNIX® System V Release 4 Programmer's Manual, 1990, (Englewood Cliffs, New Jersey), AT&T UNIX System Laboratories, Inc., Prentice Hall.
[2]: Magic Garden, The Magic Garden Explained: The Internals of UNIX® System V Release 4 / An Open Systems Design, 1994, (Australia), B. Goodheart, J. Cox, Prentice Hall. [ISBN 0-13-098138-9]
[3]: Advanced Programming in the UNIX®Environment, 15th edition, December 1997, (Reading, Massachusetts), W. R. Stevens, Addison Wesley. [ISBN 0-201-56317-7]